Because of various circumstances such as injury, trauma, degeneration or the like, it becomes necessary to immobilize one or more vertebrae with respect to other vertebrae of the spine. This includes vertebrae of the lumbar, thoracic and the cervical areas. Various devices have been devised in order to accomplish this result.
While these devices are adequate to immobilize lumbar vertebrae, thoracic vertebrae, and some of the cervical vertebrae of the spine, they are particularly deficient in effectively immobilizing the C1 cervical vertebra relative to the C2 cervical vertebra. The C1 or atlas vertebra is the topmost cervical vertebra of the human spine and, along with the C2 or axis vertebra forms the joint connecting the skull and spine. A major difference of the atlas cervical vertebra relative to other vertebrae is that it does not have a body but is fused with the C2 vertebra. The C2 vertebra forms the pivot upon which C1 rotates. It is because of these peculiarities that prior art vertebral immobilization devices are inadequate for use with a C1 to C2 immobilization.
In view of the above, it can be appreciated that it would be desirable to have a better device, method and manner of immobilizing the C1 vertebra to the C2 vertebra.
The present invention sufficiently accomplishes these means.